The Cambria slab of the central California coast consists of about 4,000 m of massive, thick-bedded, unmetamorphosed Upper Cretaceous sandstone characteristic of deposition within channel facies of a submarine fan system. Sedimentary petrology indicates a provenance of uplifted sedimentary-metasedimentary and plutonic terranes. In addition, a glaucophane schist clast and large red and green chert clasts suggest partial derivation from local Franciscan assemblage sources.
A trench-slope basin model best characterizes the sedimentary and tectonic environment of the Cambria and related slabs. Deposition occurred on an unstable accretionary basement, followed by tectonic incorporation of blocks of the Cambria slab into the Franciscan melange.